1. Field of the Invention
The invention disclosed broadly relates to telecommunications and more particularly relates to secure email delivery.
2. Related Art
The current art defines methods by which encrypted email may be transmitted from a sender to one or more recipients on a communications network. This provides confidentiality and prevents a computer hacker from reading the contents of that message. In addition, authentication features allow a recipient to validate that a message was actually sent by a specific individual. Pretty Good Privacy (PGP) and Privacy Enhanced Email (PEM) are examples of technologies that currently provide these features.
However, it is possible for a computer hacker to infer useful information about an email transmission by (a) looking at the time when an email is sent and (b) looking at the source and destination IP addresses. For example, an encrypted email sent by a stock broker can contain a buy or sell recommendation. Although a computer hacker cannot read the message contents, he or she can look at current news and market conditions and possibly infer the contents of the message. In addition, if a computer hacker has some knowledge of the clients of a broker, he or she can infer information by determining the source and destination of IP packets that are sent by the broker.